--- a/mxtool/mx.py	Fri Jan 16 14:24:04 2015 +0100
+++ b/mxtool/mx.py	Sat Jan 17 11:26:18 2015 +0100
@@ -34,7 +34,6 @@
 """
 
 import sys, os, errno, time, subprocess, shlex, types, StringIO, zipfile, signal, xml.sax.saxutils, tempfile, fnmatch, platform
-import multiprocessing
 import textwrap
 import socket
 import tarfile
@@ -62,6 +61,22 @@
         raise error
     return output
 
+# Support for jython
+def is_jython():
+    return sys.platform.startswith('java')
+
+if not is_jython():
+    import multiprocessing
+
+def cpu_count():
+    if is_jython():
+        from java.lang import Runtime
+        runtime = Runtime.getRuntime()
+        return runtime.availableProcessors()
+    else:
+        return multiprocessing.cpu_count()
+
+
 try: subprocess.check_output
 except: subprocess.check_output = check_output
 
@@ -251,6 +266,9 @@
         self.name = name
         self.suite = suite
 
+    def __cmp__(self, other):
+        return cmp(self.name, other.name)
+
     def __str__(self):
         return self.name
 
@@ -307,7 +325,7 @@
         Add the transitive set of dependencies for this project, including
         libraries if 'includeLibs' is true, to the 'deps' list.
         """
-        return self._all_deps_helper(deps, [], includeLibs, includeSelf, includeJreLibs, includeAnnotationProcessors)
+        return sorted(self._all_deps_helper(deps, [], includeLibs, includeSelf, includeJreLibs, includeAnnotationProcessors))
 
     def _all_deps_helper(self, deps, dependants, includeLibs, includeSelf=True, includeJreLibs=False, includeAnnotationProcessors=False):
         if self in dependants:
@@ -527,7 +545,7 @@
                 # Inherit annotation processors from dependencies
                 aps.update(p.annotation_processors())
 
-            self._annotationProcessors = list(aps)
+            self._annotationProcessors = sorted(list(aps))
         return self._annotationProcessors
 
     """
@@ -589,8 +607,9 @@
         return d.hexdigest()
 
 def download_file_with_sha1(name, path, urls, sha1, sha1path, resolve, mustExist, sources=False, canSymlink=True):
+    canSymlink = canSymlink and not (get_os() == 'windows' or get_os() == 'cygwin')
     def _download_lib():
-        cacheDir = get_env('MX_CACHE_DIR', join(_opts.user_home, '.mx', 'cache'))
+        cacheDir = _cygpathW2U(get_env('MX_CACHE_DIR', join(_opts.user_home, '.mx', 'cache')))
         if not exists(cacheDir):
             os.makedirs(cacheDir)
         base = basename(path)
@@ -680,7 +699,7 @@
         """
         if includeJreLibs and includeSelf and not self in deps:
             deps.append(self)
-        return deps
+        return sorted(deps)
 
 class Library(BaseLibrary):
     def __init__(self, suite, name, path, optional, urls, sha1, sourcePath, sourceUrls, sourceSha1, deps):
@@ -753,10 +772,10 @@
         Add the transitive set of dependencies for this library to the 'deps' list.
         """
         if not includeLibs:
-            return deps
+            return sorted(deps)
         childDeps = list(self.deps)
         if self in deps:
-            return deps
+            return sorted(deps)
         for name in childDeps:
             assert name != self.name
             dep = library(name)
@@ -764,7 +783,7 @@
                 dep.all_deps(deps, includeLibs=includeLibs, includeJreLibs=includeJreLibs, includeAnnotationProcessors=includeAnnotationProcessors)
         if not self in deps and includeSelf:
             deps.append(self)
-        return deps
+        return sorted(deps)
 
 class HgConfig:
     """
@@ -961,7 +980,7 @@
                 abort('Attribute "' + name + '" for ' + context + ' must be a list')
             return v
 
-        for name, attrs in projsMap.iteritems():
+        for name, attrs in sorted(projsMap.iteritems()):
             context = 'project ' + name
             srcDirs = pop_list(attrs, 'sourceDirs', context)
             deps = pop_list(attrs, 'dependencies', context)
@@ -983,14 +1002,14 @@
             p.__dict__.update(attrs)
             self.projects.append(p)
 
-        for name, attrs in jreLibsMap.iteritems():
+        for name, attrs in sorted(jreLibsMap.iteritems()):
             jar = attrs.pop('jar')
             # JRE libraries are optional by default
             optional = attrs.pop('optional', 'true') != 'false'
             l = JreLibrary(self, name, jar, optional)
             self.jreLibs.append(l)
 
-        for name, attrs in libsMap.iteritems():
+        for name, attrs in sorted(libsMap.iteritems()):
             context = 'library ' + name
             if "|" in name:
                 if name.count('|') != 2:
@@ -1011,7 +1030,7 @@
             l.__dict__.update(attrs)
             self.libs.append(l)
 
-        for name, attrs in distsMap.iteritems():
+        for name, attrs in sorted(distsMap.iteritems()):
             context = 'distribution ' + name
             path = attrs.pop('path')
             sourcesPath = attrs.pop('sourcesPath', None)
@@ -1289,11 +1308,29 @@
             result = result.replace('encoding="UTF-8"?>', 'encoding="UTF-8" standalone="' + str(standalone) + '"?>')
         return result
 
+def get_jython_os():
+    from java.lang import System as System
+    os_name = System.getProperty('os.name').lower()
+    if System.getProperty('isCygwin'):
+        return 'cygwin'
+    elif os_name.startswith('mac'):
+        return 'darwin'
+    elif os_name.startswith('linux'):
+        return 'linux'
+    elif os_name.startswith('sunos'):
+        return 'solaris'
+    elif os_name.startswith('win'):
+        return 'windows'
+    else:
+        abort('Unknown operating system ' + os_name)
+
 def get_os():
     """
     Get a canonical form of sys.platform.
     """
-    if sys.platform.startswith('darwin'):
+    if is_jython():
+        return get_jython_os()
+    elif sys.platform.startswith('darwin'):
         return 'darwin'
     elif sys.platform.startswith('linux'):
         return 'linux'
@@ -1313,7 +1350,7 @@
     """
     if p is None or get_os() != "cygwin":
         return p
-    return subprocess.check_output(['cygpath', '-w', p]).strip()
+    return subprocess.check_output(['cygpath', '-a', '-w', p]).strip()
 
 def _cygpathW2U(p):
     """
@@ -1322,7 +1359,7 @@
     """
     if p is None or get_os() != "cygwin":
         return p
-    return subprocess.check_output(['cygpath', '-u', p]).strip()
+    return subprocess.check_output(['cygpath', '-a', '-u', p]).strip()
 
 def _separatedCygpathU2W(p):
     """
@@ -1665,6 +1702,7 @@
         self.add_argument('-p', '--primary-suite-path', help='set the primary suite directory', metavar='<path>')
         self.add_argument('--dbg', type=int, dest='java_dbg_port', help='make Java processes wait on <port> for a debugger', metavar='<port>')
         self.add_argument('-d', action='store_const', const=8000, dest='java_dbg_port', help='alias for "-dbg 8000"')
+        self.add_argument('--backup-modified', action='store_true', help='backup generated files if they pre-existed and are modified')
         self.add_argument('--cp-pfx', dest='cp_prefix', help='class path prefix', metavar='<arg>')
         self.add_argument('--cp-sfx', dest='cp_suffix', help='class path suffix', metavar='<arg>')
         self.add_argument('--J', dest='java_args', help='Java VM arguments (e.g. --J @-dsa)', metavar='@<args>')
@@ -1848,11 +1886,11 @@
         # can use os.killpg() to kill the whole subprocess group
         preexec_fn = None
         creationflags = 0
-        if get_os() == 'windows':
-            creationflags = subprocess.CREATE_NEW_PROCESS_GROUP
-        else:
-            preexec_fn = os.setsid
-
+        if not is_jython():
+            if get_os() == 'windows':
+                creationflags = subprocess.CREATE_NEW_PROCESS_GROUP
+            else:
+                preexec_fn = os.setsid
         def redirect(stream, f):
             for line in iter(stream.readline, ''):
                 f(line)
@@ -2080,7 +2118,7 @@
         javaSource = join(myDir, 'ClasspathDump.java')
         if not exists(join(outDir, 'ClasspathDump.class')):
             subprocess.check_call([self.javac, '-d', _cygpathU2W(outDir), _cygpathU2W(javaSource)], stderr=subprocess.PIPE, stdout=subprocess.PIPE)
-        self._bootclasspath, self._extdirs, self._endorseddirs = [x if x != 'null' else None for x in subprocess.check_output([self.java, '-cp', _separatedCygpathU2W(outDir), 'ClasspathDump'], stderr=subprocess.PIPE).split('|')]
+        self._bootclasspath, self._extdirs, self._endorseddirs = [x if x != 'null' else None for x in subprocess.check_output([self.java, '-cp', _cygpathU2W(outDir), 'ClasspathDump'], stderr=subprocess.PIPE).split('|')]
         if not self._bootclasspath or not self._extdirs or not self._endorseddirs:
             warn("Could not find all classpaths: boot='" + str(self._bootclasspath) + "' extdirs='" + str(self._extdirs) + "' endorseddirs='" + str(self._endorseddirs) + "'")
         self._bootclasspath = _filter_non_existant_paths(self._bootclasspath)
@@ -2228,7 +2266,7 @@
     def is_alive(p):
         if isinstance(p, subprocess.Popen):
             return p.poll() is None
-        assert isinstance(p, multiprocessing.Process), p
+        assert is_jython() or isinstance(p, multiprocessing.Process), p
         return p.is_alive()
 
     for p, args in _currentSubprocesses:
@@ -2288,6 +2326,9 @@
         if old == content:
             return False
 
+        if existed and _opts.backup_modified:
+            shutil.move(path, path + '.orig')
+
         with open(path, 'wb') as f:
             f.write(content)
 
@@ -2434,7 +2475,7 @@
     parser = parser if parser is not None else ArgumentParser(prog='mx build')
     parser.add_argument('-f', action='store_true', dest='force', help='force build (disables timestamp checking)')
     parser.add_argument('-c', action='store_true', dest='clean', help='removes existing build output')
-    parser.add_argument('-p', action='store_true', dest='parallelize', help='parallelizes Java compilation')
+    parser.add_argument('-p', action='store_true', dest='parallelize', help='parallelizes Java compilation if possible')
     parser.add_argument('--source', dest='compliance', help='Java compliance level for projects without an explicit one')
     parser.add_argument('--Wapi', action='store_true', dest='warnAPI', help='show warnings about using internal APIs')
     parser.add_argument('--projects', action='store', help='comma separated projects to build (omit to build all projects)')
@@ -2454,6 +2495,11 @@
 
     args = parser.parse_args(args)
 
+    if is_jython():
+        if args.parallelize:
+            logv('[multiprocessing not available in jython]')
+            args.parallelize = False
+
     jdtJar = None
     if not args.javac and args.jdt is not None:
         if not args.jdt.endswith('.jar'):
@@ -2610,7 +2656,7 @@
                 t._d = None
             return sorted(tasks, compareTasks)
 
-        cpus = multiprocessing.cpu_count()
+        cpus = cpu_count()
         worklist = sortWorklist(tasks.values())
         active = []
         failed = []
@@ -3564,10 +3610,10 @@
         elif dep.isProject():
             projectDeps.add(dep)
 
-    for dep in containerDeps:
+    for dep in sorted(containerDeps):
         out.element('classpathentry', {'exported' : 'true', 'kind' : 'con', 'path' : dep})
 
-    for dep in libraryDeps:
+    for dep in sorted(libraryDeps):
         path = dep.path
         dep.get_path(resolve=True)
 
@@ -3585,7 +3631,7 @@
         if libFiles:
             libFiles.append(path)
 
-    for dep in projectDeps:
+    for dep in sorted(projectDeps):
         out.element('classpathentry', {'combineaccessrules' : 'false', 'exported' : 'true', 'kind' : 'src', 'path' : '/' + dep.name})
 
     out.element('classpathentry', {'kind' : 'output', 'path' : getattr(p, 'eclipse.output', 'bin')})
@@ -4461,7 +4507,7 @@
 
     if annotationProcessorProfiles:
         compilerXml.open('annotationProcessing')
-        for processors, modules in annotationProcessorProfiles.items():
+        for processors, modules in sorted(annotationProcessorProfiles.iteritems()):
             compilerXml.open('profile', attributes={'default': 'false', 'name': '-'.join(processors), 'enabled': 'true'})
             compilerXml.element('sourceOutputDir', attributes={'name': 'src_gen'})  # TODO use p.source_gen_dir() ?
             compilerXml.element('outputRelativeToContentRoot', attributes={'value': 'true'})
@@ -5236,11 +5282,12 @@
     c, _ = _commands[command][:2]
     def term_handler(signum, frame):
         abort(1)
-    signal.signal(signal.SIGTERM, term_handler)
+    if not is_jython():
+        signal.signal(signal.SIGTERM, term_handler)
 
     def quit_handler(signum, frame):
         _send_sigquit()
-    if get_os() != 'windows':
+    if not is_jython() and get_os() != 'windows':
         signal.signal(signal.SIGQUIT, quit_handler)
 
     try: